Modern datacenter applications often require networks to provide high throughput and low latency, simultaneously. Unfortunately, traditional Transmission Control Protocol (TCP)/Internet Protocol (IP) stacks implemented in the data center and the network for communications often fail to meet these simultaneous requirements. Remote direct memory access (RDMA) is a promising technology to meet the above challenge; however, RDMA and also storage networks in datacenters, often rely on Priority-based Flow Control (PFC) to enable a drop-free network. PFC can lead to poor performance of applications hosted in the data center due to problems such as head-of-line blocking and unfairness computations. Quantized Congestion Notification (QCN) was introduced and standardized at IEEE 802.1 working group (IEEE 802.1Qau) to solve the limitation of PFC. QCN, however, is an Open System Interconnect (OSI) layer 2-based technology, and in IP-routed datacenters, its application is limited. The industry needs an effective and fast reacting mechanism to provide OSI layer 3 congestion control.